Make sure we're matching the same way.

Ruby's regular expression is unicode aware, therefore 'å' also
matches against /\p{alnum}/. If we want only ASCII-7bit, use
[a-zA-Z0-9]+ so they always match the same thing

db/fixtures/development/19_environments.rb

@@ -30,14 +30,14 @@ class Gitlab::Seeder::Environments
   def create_merge_request_review_deployments!
     @project
       .merge_requests
-      .select { |mr| mr.source_branch.match(/\p{Alnum}+/) }
+      .select { |mr| mr.source_branch.match(/[^a-zA-Z0-9]+/) }
       .sample(4)
       .each do |merge_request|
       next unless merge_request.diff_head_sha
 
       create_deployment!(
         merge_request.source_project,
-        "review/#{merge_request.source_branch.gsub(/[^a-zA-Z0-9]/, '')}",
+        "review/#{merge_request.source_branch.gsub(/[^a-zA-Z0-9]+/, '')}",
         merge_request.source_branch,
         merge_request.diff_head_sha
       )